1. Field of the Invention
The present invention relates to a process for oxidizing cellulose with a solution of nitrogen dioxide in one or more hydrofluoroether solvents.
2. Description of the Related Art
The oxidation of cellulose by reaction of cellulose with nitrogen dioxide is a well known process. A patent which provides a comprehensive description of the development of this technology is U.S. Pat. No. 5,180,398, the subject matter of which is incorporated herein by reference. The improvement of U.S. Pat. No. 5,180,398 is asserted to reside in the use of a particular class of solvents, notably perfluorocarbon solvents, in carrying out the otherwise known reaction. The use of perfluorocarbon solvents is said to be an improvement over the use of various closely analogous solvents including chlorinated hydrocarbons and chlorinated fluorocarbons as disclosed in U.S. Pat. Nos. 3,364,200 and 4,347,057. Ethers are said to be ineffective as solvents for the cellulose oxidation.